对使用Map的优化

背景

在苏州实训课上，要求做世界杯的排名次序。其中，要将A-H组的List放入Map中

自己想法

 //定义A-H组的集合
        List<NationalityTeam> aList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> bList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> cList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> dList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> eList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> fList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> gList = new ArrayList<NationalityTeam>();
        List<NationalityTeam> hList = new ArrayList<NationalityTeam>();

        //将A-H组放入map中
        Map<String,List<NationalityTeam>> nationalityTeamMap = new HashMap<String,List<NationalityTeam>>();
        nationalityTeamMap.put("A组",aList);
        nationalityTeamMap.put("B组",bList);
        nationalityTeamMap.put("C组",cList);
        nationalityTeamMap.put("D组",dList);
        nationalityTeamMap.put("E组",eList);
        nationalityTeamMap.put("F组",fList);
        nationalityTeamMap.put("G组",gList);
        nationalityTeamMap.put("H组",hList);

老师优化后的代码

//把国家队放进Map
        Map<Character,List<NationalityTeam>> nationalTeam = new HashMap<Character, List<NationalityTeam>>();
        char start = 'A';
        for(int i = 0; i < 8; i++){
            nationalTeam.put(start++,new ArrayList<NationalityTeam>());
        }

总结

明显自己写的太繁琐，虽然结果是一样的，但代码量实在太大,在

转载于:https://my.oschina.net/u/3669883/blog/1838258